Method and apparatus for displaying an image of a device based on radio waves

ABSTRACT

The present invention relates to an information processing apparatus and method, and a program in which information can be reliably exchanged when performing wireless communication by allowing a user to know a communication distance at which devices can be connected. A communication unit  28  performs Bluetooth communication with a communication unit, which serves as a Bluetooth module, provided for a cellular telephone. A CPU  21  displays an image corresponding to the cellular telephone based on the input level of Bluetooth radio waves transmitted from the cellular telephone. For example, when the input level of the radio waves transmitted from the cellular telephone is equal to the maximum input, the CPU  21  sets the level of transparency to be 0, and displays the image corresponding to the cellular telephone on an LCD  32  so that a background image is not transmitted at all. When the input level of the radio waves is almost equal to the reception sensitivity, the CPU  21  displays the image corresponding to the cellular telephone on the LCD  32  by setting the level of transparency to be 90% so as to transmit the background image. The present invention can be applied to an information processing apparatus, for example, a personal computer, a PDA, or a cellular telephone.

TECHNICAL FIELD

The present invention relates to information processing apparatuses andmethods, and recording media, and more particularly, to an informationprocessing apparatus and method, and a recording medium in whichcommunication can be performed via radio waves.

BACKGROUND ART

Cellular telephones and PDAs (Personal Digital Assistants) are cominginto widespread use. As a result of this, users exchange informationbetween a plurality of such devices more frequently.

Hitherto, when exchanging information as described above, information issent and received by connecting devices with each other via a cradle ora cable or by allowing infrared transmitters/receivers to face eachother.

However, wired connection makes the operation troublesome andcomplicated, and also, a connector compatible with each device type mustbe prepared.

In infrared communication, if the user inadvertently passes through theinfrared transmission channel, communication is interrupted.

It has been suggested that wireless communication is performed between aplurality of devices by using a wireless LAN (Local Area Network) or ashort-distance wireless LAN, for example, Bluetooth®.

However, when exchanging information, for example, between a PDA ownedby the user and a device installed in front of the user, the user isunable to know whether communication can be made between the devicesunless he/she actually perform communication. In this manner, whenperforming wireless communication, the user is unable to know acommunication distance at which information can be exchanged byconnecting devices.

DISCLOSURE OF INVENTION

Accordingly, in view of this background, it is an object of the presentinvention to reliably exchange information when performing wirelesscommunication by allowing a user to know a communication distance atwhich devices can be connected.

An information processing apparatus including: communication means forcommunicating with an electronic device via radio waves; obtaining meansfor obtaining identification information concerning the electronicdevice; and display control means for controlling, among a plurality ofelectronic devices, an image of the configuration of the electronicdevice specified from the identification information obtained by theobtaining means to be displayed based on the input level of the radiowaves transmitted from the electronic device located in a communicationrange of communication performed by the communication means.

The information processing apparatus may further include: detectionmeans for detecting that the electronic device is disposed in proximitywith the information processing apparatus; and obtaining means forobtaining identification information concerning the electronic devicewhen the detection means detects that the electronic device is disposedin proximity with the information processing apparatus. Thecommunication means may communicate with the electronic device based onthe identification information.

The display control means may control the image to be displayed with alevel of transparency corresponding to the input level of the radiowaves.

The display control means may control the image to be displayed at aposition corresponding to the input level of the radio waves.

The display control means may control the image to be displayed with asize corresponding to the input level of the radio waves.

The display control means may control the image to be displayed with alevel of resolution corresponding to the input level of the radio waves.

The display control means may control the image to be displayed with alevel of saturation corresponding to the input level of the radio waves.

The display control means may control the image to be displayed byperforming mosaic processing on the image in accordance with the inputlevel of the radio waves.

An information processing method including: a communication processingstep of communicating with an electronic device via radio waves; anobtaining processing step of obtaining identification informationconcerning the electronic device; and a display control processing stepof controlling, among a plurality of electronic devices, an image of theconfiguration of the electronic device specified from the identificationinformation obtained by processing of the obtaining processing step tobe displayed based on the input level of the radio waves transmittedfrom the electronic device located in a communication range ofcommunication performed by processing of the communication processingstep.

A program recorded on a recording medium of the present inventionincludes: a communication processing step of communicating with anelectronic device via radio waves; an obtaining processing step ofobtaining identification information concerning the electronic device;and a display control processing step of controlling, among a pluralityof electronic devices, an image of the configuration of the electronicdevice specified from the identification information obtained byprocessing of the obtaining processing step to be displayed based on theinput level of the radio waves transmitted from the electronic devicelocated in a communication range of communication performed byprocessing of the communication processing step.

According to the information processing apparatus and method, and theprogram recorded on the recording medium of the present invention,communication is performed with an electronic device via radio waves toobtain the identification information concerning the electronic device.Among a plurality of electronic devices, the display of an imagecorresponding to the electronic device specified from the identificationinformation is controlled based on the input level of the radio wavestransmitted from the electronic device located in the communicationrange.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of the configuration of an informationprocessing system to which the present invention is applied.

FIG. 2 is a block diagram illustrating an example of the configurationof a personal computer shown in FIG. 1.

FIG. 3 is a block diagram illustrating the configuration of areader/writer 33.

FIG. 4 is a block diagram illustrating the configuration of acommunication unit 28.

FIG. 5 is a block diagram illustrating the configuration of programsexecuted by the personal computer 1.

FIG. 6 is a block diagram illustrating the configuration of a cellulartelephone 11.

FIG. 7 is a block diagram illustrating the configuration of an RF tag212.

FIG. 8 illustrates an example of the functional blocks of the cellulartelephone 11.

FIG. 9 is a flowchart illustrating the processing performed by thepersonal computer in the information processing system shown in FIG. 1.

FIG. 10 is a flowchart illustrating the processing performed by thecellular telephone in the information processing system shown in FIG. 1.

FIG. 11 is a flowchart illustrating the processing performed by thepersonal computer in the information processing system shown in FIG. 1.

FIG. 12 is a flowchart illustrating the processing performed by thecellular telephone in the information processing system shown in FIG. 1.

FIG. 13 illustrates the sending and receiving of data between thecellular telephone and the personal computer.

FIG. 14 is a flowchart illustrating the processing performed by thecellular telephone in the example shown in FIG. 13.

FIG. 15 is a flowchart illustrating the processing performed by thepersonal computer in the example shown in FIG. 13.

FIG. 16 illustrates an example of the display indicating thecommunication status.

FIG. 17 illustrates an example of the display indicating thecommunication status.

FIG. 18 illustrates an example of the display indicating thecommunication status.

FIG. 19 is a flowchart illustrating the processing for displaying theradio wave status.

FIG. 20 illustrates an example of the display indicating thecommunication status.

FIG. 21 illustrates an example of the display indicating thecommunication status.

FIG. 22 illustrates an example of the display indicating thecommunication status.

FIG. 23 is a flowchart illustrating the processing for displaying theradio wave status.

FIG. 24 illustrates an example of the configuration of a communicationsystem to which the present invention is applied.

FIG. 25 is a block diagram illustrating an example of the configurationof a PDA shown in FIG. 24.

FIG. 26 is a block diagram illustrating an example of a wireless moduleshown in FIG. 25.

FIG. 27 is a flowchart illustrating the operation of the communicationsystem shown in FIG. 24.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 illustrates an example of the configuration of an informationprocessing system to which the present invention is applied. In thisexample, a personal computer 1 is provided with an input display unit 2and a main unit 3 connected to the input display unit 2. The inputdisplay unit 2 displays predetermined information, and also,predetermined information can be input by operating, for example, a pen(not shown) on the input display unit 2.

If necessary, the user can place, for example, a cellular telephone 11,on the input display unit 2 so as to send and receive data between thecellular telephone 11 and the personal computer 1.

FIG. 2 illustrates an example of the configuration of the personalcomputer 1. A CPU (Central Processing Unit) 21 executes various types ofprocessing according to programs stored in a ROM (Read Only Memory) 22or a storage unit 26. A RAM (Random Access Memory) 23 suitably storesprograms, data, etc. executed by the CPU 21. The CPU 21, the ROM 22, andthe RAM 23 are connected to each other via a bus 24. An input/outputinterface 25 is also connected to the bus 24. The input/output interface25 is connected, not only to the input display unit 2, but also to thestorage unit 26 formed of, for example, a hard disk, and to acommunication unit 27 that communicates with other devices via, forexample, a telephone line.

A communication unit 28 is a so-called “Bluetooth module”. Thecommunication unit 28 performs Bluetooth communication with, forexample, a communication unit 213 (see FIG. 6), which is a Bluetoothmodule, provided for the cellular telephone 11.

Bluetooth is a wireless communication standard standardized by theBluetooth SIG (Special Interest Group), and a device communicates withother devices provided with Bluetooth modules (hereinafter sometimesreferred to as “Bluetooth devices”) by using the 2.4 GHz band (ISM(Industrial Science Medical) band).

A network formed by Bluetooth is referred to as “piconet” or“scatternet” formed of a plurality of piconets connected with each otherdepending on the network type, and in such a network, Bluetooth devices,which serve as a master and slaves, are provided. A Bluetooth device,which serves as a master, is simply referred to as a “master”, andBluetooth devices, which serve as slaves, are simply referred to as“slaves”.

After forming a piconet, in order to send and receive various items ofinformation, it is necessary for all the Bluetooth devices in thepiconet to establish synchronization in the frequency domain and in thetime domain.

Establishing synchronization in the frequency domain and in the timedomain is briefly described.

In Bluetooth, for example, a master sends a signal to a slave by using afrequency range of 79 MHz. In this case, instead of sending informationby using all the frequency range, the master sends the information byrandomly changing (hopping) this frequency range in units of 1 MHz.

The slave, which is the receiving device, receives the information sentfrom the master by suitably changing the reception frequency insynchronization with the randomly changing transmission frequency of themaster.

The frequency pattern changed by the master and the slave is referred toas the “frequency hopping pattern”. When the frequency hopping patternis shared between the master and the slave, it means that thesynchronization in the frequency domain is established.

In Bluetooth, since a master and a plurality of slaves performcommunication, the communication channel between the master and theslaves is divided in a time-division multiplexing manner in units of 625μs. The time intervals of the time units of 625 μs are referred to as“time slots”, and when the time slot is shared, it means that thesynchronization in the time domain is established.

All the slaves each calculate the frequency hopping pattern forestablishing synchronization in the frequency domain based on theBluetooth address of the master, and also adds an offset to theBluetooth clock managed by the slave based on the Bluetooth clock of themaster so as to provide timing for the time slot for establishingsynchronization in the time domain.

The Bluetooth address is represented by 48 bits unique to each Bluetoothdevice, and based on this address, the frequency hopping pattern isuniquely calculated. The Bluetooth clock is managed by each Bluetoothdevice.

Accordingly, before forming a piconet, various items of informationincluding the Bluetooth addresses and the Bluetooth clocks forestablishing synchronization in the frequency domain and in the timedomain, respectively, are sent and received between the master and theslaves.

Referring back to FIG. 2, the input display unit 2 is provided with atransparent tablet 31 for detecting the operation of a pen performed bythe user, and an LCD (Liquid Crystal Display) 32 disposed under thetablet 31 for displaying images of, for example, characters andgraphics. The input display unit 2 is also provided with a reader/writer33 that communicates with an RF tag 212 (FIG. 6) provided for thecellular telephone 11.

A drive 29 is connected to the input/output interface 25, and a magneticdisk 41, an optical disc 42, a magneto-optical disk 43, or asemiconductor memory 44 is attached to this drive 29 when necessary. Aprogram read from the magnetic disk 41, the optical disc 42, themagneto-optical disk 43, or the semiconductor memory 44 is supplied fromthe drive 29 to the storage unit 26 via the input/output interface 25.

FIG. 3 is a block diagram illustrating an example of a detailedconfiguration of the reader/writer 33.

An IC 81 is formed of a CPU 91, an SPU (Signal Processing Unit) 92, anSCC (Serial Communication Controller) 93, and a memory 94. The memory 94includes a ROM 101 and a RAM 102. The CPU 91, the SPU 92, the SCC 93,and the memory 94 are connected to each other via a bus 95.

The CPU 91 expands a control program stored in the ROM 101 to the RAM102, and performs various types of processing based on response datasent from the RF tag 212 of the cellular telephone 11, which isdescribed below, or a control signal supplied from the CPU 21 shown inFIG. 2. For example, the CPU 91 generates a command to be sent to the RFtag 212 and outputs it to the SPU 92 via the bus 95, or authenticatesdata sent from the RF tag 212.

When the cellular telephone 11 is placed in proximity with the personalcomputer 1, and then, when the name of the Bluetooth device is reportedaccording to the processing of the various elements, which is describedbelow, the CPU 91 informs the communication unit 28 that the cellulartelephone 11 is placed close to the personal computer 1 based on aninstruction of the CPU 21.

When response data from the RF tag 212 is supplied from a demodulator84, the SPU 92 performs, for example, BPSK (Binary Phase Shift Keying)demodulation, on that data, and supplies the resulting data to the CPU91. When a command to be sent to the RF tag 212 is supplied via the bus95, the SPU 92 performs modulation (primary modulation) on that command,and outputs the resulting data to a modulator 82.

The SCC 93 outputs data supplied from the CPU 21 to the CPU 91 via thebus 95, and outputs data supplied from the CPU 91 via the bus 95 to theCPU 21.

The modulator 82 performs ASK (Amplitude Shift Keying) modulation on thecarrier wave of a predetermined frequency supplied from an oscillatorcircuit (OSC) 83 as the secondary modulation based on data supplied fromthe SPU 92, and outputs the generated modulation wave from an antenna 85as electromagnetic waves. Meanwhile, the demodulator 84 demodulates amodulated wave (ASK-modulated wave) obtained via the antenna 85 andoutputs the demodulated data to the SPU 92.

The antenna 85 radiates a predetermined electromagnetic wave, and then,based on a change of the load with respect to the electromagnetic wave,the antenna 85 detects whether the RF tag 212 (cellular telephone 11)has been placed in proximity with the personal computer 1. When the RFtag 212 is placed in proximity with the personal computer 1, the antenna85 sends and receives various items of data to and from the RF tag 212.

FIG. 4 is a block diagram illustrating an example of a detailedconfiguration of the communication unit 28, which serves as a Bluetoothmodule.

A CPU 121 expands a control program stored in a ROM 122 into a RAM 123,and controls the overall operation of the communication unit 28. The CPU121, the ROM 122, and the RAM 123 are connected to each other via a bus125, and a flash memory 124 is connected to the bus 125.

The flash memory 124 stores therein the name of a Bluetooth device thatis set for each Bluetooth device and can be changed according to theuser's favorite, and also stores the Bluetooth address unique to eachBluetooth device.

The Bluetooth address is a 48-bit identifier, which is used for varioustypes of processing for managing Bluetooth devices since it is inherentin (unique to) each Bluetooth device.

For example, as discussed above, for establishing synchronization in apiconet, it is necessary for all the slaves to obtain informationconcerning the frequency hopping pattern of the master. This frequencyhopping pattern can be calculated by the slaves based on the Bluetoothaddress of the master.

More specifically, the Bluetooth address is formed of the lower 24-bitLAP (Low Address Part), the next 8-bit UAP (Upper Address Part), and theremaining 16-bit NAP (Non-significant Address Part). For calculating thefrequency hopping pattern, a total of 28 bits consisting of the whole 24bits of LAP and the lower 4 bits of UAP are used.

Each slave is able to calculate the frequency hopping pattern based onthe above-described 28 bits of the Bluetooth address of the master,which is obtained when paging the master to establish synchronization inthe piconet, and based on the Bluetooth clock reported from the master.

In this frequency hopping pattern, the inquiry frequency hopping patternused when making an inquiry, the paging frequency hopping pattern usedwhen paging, and the channel frequency hopping pattern used whenperforming communication between the master and a slave afterestablishing synchronization in the piconet are defined. The threefrequency hopping patterns are hereinafter simply referred to as the“frequency hopping pattern” unless they should be distinguished fromeach other.

The flash memory 124 stores link keys for authenticating a Bluetoothdevice, which is a communicating party, or for encrypting data to besent after establishing synchronization in a piconet, and provides thestored link keys to the CPU 121 if necessary.

An input/output interface 126 manages input/output of data supplied fromthe CPU 21 shown in FIG. 2 or data supplied from a baseband controller127 based on an instruction from the CPU 121.

The baseband controller 127 outputs data supplied from the input/outputinterface 126 to a GFSK (Gaussian Frequency Shift Keying) modulator 141so as to send the data to the cellular telephone 11, and outputs datasupplied from a GFSK demodulator 147 to the bus 125 or the input/outputinterface 126.

The GFSK modulator 141 restricts high frequency components of datasupplied from the baseband controller 127 by using a filter so as toperform frequency modulation on the data as the primary modulation, andoutputs the resulting data to a spread spectrum unit 142.

The spread spectrum unit 142 switches between the frequency carriersbased on the frequency hopping pattern calculated as described above andreported from a hopping synthesizer 145, performs spread spectrum on thesupplied data, and then outputs the resulting signal to a communicationcontroller 143. In Bluetooth, the spread spectrum unit 142 sends data byperforming frequency hopping in every 625 μs.

The communication controller 143 sends the spread-spectrum signal froman antenna 144 by using the 2.4 GHz band. The communication controller143 also outputs a received signal from the antenna 144 to an inversespread spectrum unit 146.

The inverse spread spectrum unit 146 hops the reception frequency basedon the frequency hopping pattern reported from the hopping synthesizer145 so as to obtain, for example, a signal from the cellular telephone11. The inverse spread spectrum unit 146 also performs inverse spreadspectrum on a signal from the cellular telephone 11, and outputs thereproduced signal to the GFSK demodulator 147. The GFSK demodulator 147performs GFSK demodulation on the signal supplied from the inversespread spectrum unit 146, and outputs the resulting data to the basebandcontroller 127.

FIG. 5 is a block diagram illustrating the configuration of programsexecuted by the personal computer 1. An operating system (basic programsoftware) 161 is, for example, Windows® Me, Windows® 2000 by MicrosoftCorporation, or Mac OS® by Apple Computer Inc., and controls the basicoperation of the computer.

A reader/writer control program 162 controls the reader/writer 33 so asto detect the presence of a terminal integrating the RF tag 212 thereinwhich is placed in proximity with the personal computer 1 or to send andreceive various items of information to and from that terminal viaelectromagnetic waves.

A Bluetooth control program 163 controls the communication unit 28 so asto, for example, detect the presence of a Bluetooth device placed inproximity with the personal computer 1 or to establish synchronizationfor communicating with that Bluetooth device.

A display control program 164 controls the display of images of, forexample, characters and graphics, on the LCD 32 of the input displayunit 2.

An e-mail program 165 sends e-mail to other devices, for example, aserver, or receives e-mail from the other devices via the communicationunit 27.

FIG. 6 illustrates an example of the configuration of the cellulartelephone 11. A CPU 201, a ROM 202, a RAM 203, a bus 204, and aninput/output interface 205 have functions basically similar to those ofthe CPU 21, the ROM 22, the RAM 23, the bus 24, and the input/outputinterface 25, respectively, of the personal computer 1 shown in FIG. 2,and an explanation thereof is thus omitted.

In the cellular telephone 11, the input/output interface 205 isconnected to an input unit 206 formed of, for example, various buttonsand switches, and is also connected to an LCD 207 for displayingpredetermined information. A storage unit 208 formed of, for example, asemiconductor memory, and a communication unit 209 for performingcommunication via a telephone line are also connected to theinput/output interface 205.

A microphone 210 records user voice therein, and a speaker 211 outputssound to the user. The RF tag 212 has a built-in IC, and communicateswith the reader/writer 33 of the personal computer 1 so as to send thename of the Bluetooth device integrated in the cellular telephone 11 tothe reader/writer 33. The RF tag 212 has the function of storing datasupplied from the reader/writer 33 in a built-in memory.

A communication unit 213 is a Bluetooth module. The communication unit213 forms, for example, a piconet with the communication unit 28 of thepersonal computer 1, and sends and receives various items of data basedon an instruction from the CPU 201.

The configuration of the communication unit 213 is similar to that ofthe communication unit 28 shown in FIG. 4, and a detailed explanationthereof is thus omitted.

FIG. 7 is a block diagram illustrating an example of a detailedconfiguration of the RF tag 212.

The RF tag 212 is formed of, for example, a one-chip IC in which anantenna 240 shown in FIG. 7 and the elements other than the antenna 240are stored. An example of the devices having a function basicallysimilar to that of the RF tag 212 is Felica®.

A CPU 231 expands a control program stored in a ROM 232 into a RAM 233so as to control the overall operation of the RF tag 212. Whenelectromagnetic waves radiating from the reader/writer 33 are receivedby the antenna 240, the CPU 231 reports ID information set in the RF tag212 to the reader/writer 33 accordingly.

The setting of the ID information can be changed as desired, and the IDinformation contains, for example, the same name as the name of theBluetooth device set in the communication unit 213 (cellular telephone11), which serves as a Bluetooth module, or a name containing thatBluetooth device name.

In FIG. 7, a data sender 237, a BPSK modulator 238, a BPSK demodulator241, and a data receiver 242 correspond to the SPU 92 of thereader/writer 33 shown in FIG. 3, and an ASK modulator 252 and an ASKdemodulator 253 correspond to the modulator 82 and the demodulator 84,respectively. The basic processing is similar to that described above,and a detailed explanation is thus omitted.

For example, when the cellular telephone 11 is placed in proximity withthe personal computer 1, ID information is read from an EEPROM 234 andis output to the data sender 237. The ID information supplied to thedata sender 237 is subjected to BPSK modulation in the BPSK modulator238 as the primary modulation, and is then output to the ASK modulator252.

The ASK modulator 252, for example, turns ON/OFF a predeterminedswitching device in accordance with the data supplied from the BPSKmodulator 238 so as to change the load of the antenna 240. The ASKmodulator 252 then performs ASK modulation on a modulation wave from thereader/writer 33 received by the antenna 240 so as to send the modulatedcomponents to the reader/writer 33 (changes the terminal voltage of theantenna 85 of the reader/writer 33).

In addition to the reporting of the ID information to the personalcomputer 1, the RF tag 212 performs various types of processing, forexample, authentication processing with the reader/writer 33 andencryption processing of data to be sent.

FIG. 8 illustrates an example of functional blocks of the cellulartelephone 11.

A host program 271 provides basic functions of the cellular telephone11, for example, a calling function and an e-mail sending/receivingfunction. An RF-tag control program 272 controls the operation of the RFtag 212, and also performs various types of processing based on aninstruction from the host program 271.

For example, when the cellular telephone 11 is placed in proximity withthe personal computer 1, the RF-tag control program 272 provides set IDinformation to the reader/writer 33, and starts the communication unit213 (Bluetooth control program 273), which serves as a Bluetooth module,upon receiving electromagnetic waves from the reader/writer 33.

The Bluetooth control program 273 controls the operation of thecommunication unit 213 so as to implement communication with otherBluetooth devices.

The operations performed by the personal computer 1 and the cellulartelephone 11 are described below with reference to the flowcharts ofFIGS. 9 and 10. When the user wishes to send and receive data betweenthe cellular telephone 11 and the personal computer 1, he/she places thecellular telephone 11 at a predetermined position (at a position,indicated by the broken lines in FIG. 1, in which the reader/writer 33is disposed) of the input display unit 2.

The reader/writer 33 regularly sends electromagnetic waves atsufficiently short intervals, and when the cellular telephone 11 isplaced on the input display unit 2 (on the reader/writer 33), theequivalent impedance of the antenna integrated in the reader/writer 33changes due to the electromagnetic coupling between the reader/writer 33and the RF tag 212 of the cellular telephone 11. In step S1 of FIG. 9,under the control of the reader/writer control program 162, thereader/writer 33 monitors this impedance change so as to determinewhether the cellular telephone 11 is placed on the reader/writer 33, andwaits until the cellular telephone 11 is placed.

When the cellular telephone 11 is placed on the reader/writer 33, instep S2, the reader/writer 33 requests the cellular telephone 11 to sendthe name of the Bluetooth device corresponding to the communication unit213 under the control of the reader/writer control program 162.

In response to this request, the name of the Bluetooth device is sentfrom the cellular telephone 11, as described below. Then, in step S3,the reader/writer 33 waits until it receives the name of the Bluetoothdevice from the cellular telephone 11 under the control of thereader/writer control program 162, and upon receiving this, the processproceeds to step S4. In step S4, the reader/writer 33 supplies thereceived name of the Bluetooth device of the cellular telephone 11 tothe CPU 21. The CPU 21 then supplies the name of the Bluetooth device tothe RAM 23 and stores it therein under the control of the reader/writercontrol program 162.

Then, in step S5, the CPU 21, which executes the Bluetooth controlprogram 163, controls the communication unit 28 to connect to theBluetooth device corresponding to the device name of the cellulartelephone 11 stored in step S4, thereby setting a link required fortransferring data.

More specifically, when the communication unit 213 of the cellulartelephone 11 is in the waiting phase, the CPU 21 controls thecommunication unit 28 to inquire and page a synchronization establishingphase so as to establish synchronization with the communication unit213.

Upon establishing synchronization between the communication unit 28 andthe communication unit 213, the communication unit 28 of the personalcomputer 1 and the communication unit 213 of the cellular telephone 11shift to the communication connection phase.

The CPU 21 controls the communication unit 28 to send a control packetfor setting a communication link to the Bluetooth device correspondingto the device name of the cellular telephone 11, i.e., the communicationunit 213, among the Bluetooth devices in the piconet in which thesynchronization in the frequency domain and in the time domain isestablished, thereby establishing an ACL (Asynchronous Connection-Less)link required for the processing of the subsequent step.

Thereafter, in step S6, the personal computer 1 performs predeterminedprocessing with the cellular telephone 11 via a network. Specificexamples of the processing are described below.

Meanwhile, in step S11 of FIG. 10, the RF tag 212 of the cellulartelephone 11 determines whether electromagnetic waves from thereader/writer 33 of the personal computer 1 have been received (whetherthe cellular telephone 11 is placed on the input display unit 2 of thepersonal computer 1). If it is determined that the cellular telephone 11is placed on the input display unit 2, the process proceeds to step S12.In step S12, the RF tag 212 waits for a request to send the name of theBluetooth device under the control of the RF-tag control program 272. Asdiscussed above, the reader/writer 33 of the personal computer 1requests the cellular telephone 11 to send the name of the Bluetoothdevice in step S2. If it is determined that this request has beenreceived, the process proceeds to step S13 in which the RF tag 212 readsthe name of the Bluetooth device stored in the built-in memory and sendsit to the reader/writer 33 under the control of the RF-tag controlprogram 272.

The name of the Bluetooth device may be stored in the ROM 202 or thestorage unit 208, in which case, the name read from the ROM 202 or thestorage unit 208 by the CPU 201 is sent from the RF tag 212.

In step S14, the CPU 201 of the cellular telephone 11, which executesthe Bluetooth control program 273, waits until the communication unit 28of the personal computer 1 and the communication unit 213 are connectedto each other via Bluetooth communication (in this case, until thecommunication units 28 and 213 shift to the communication connectionphase).

If the communication unit 213 determines in step S14 that it isconnected to the communication unit 28 of the personal computer 1 viaBluetooth communication under the control of the Bluetooth controlprogram 273, the process proceeds to step S15. Since the communicationunit 28 of the personal computer 1 sends a control packet for settingthe communication link in step S5, the communication unit 213 receivesthis control packet so as to set the communication link with thepersonal computer 1.

Thereafter, the process proceeds to step S16 in which the cellulartelephone 11 performs predetermined processing with the personalcomputer 1 via a network. This processing corresponds to the processingof step S6 of FIG. 9.

In the above-described example, the name of the Bluetooth device of thecellular telephone 11 is sent and received as the ID information. An IDnumber other than the name of the Bluetooth device of the cellulartelephone 11 may be sent from the cellular telephone 11 to the personalcomputer 1, and the personal computer 1 may search for the name of theBluetooth device of the cellular telephone 11 as the network addressbased on the ID number.

FIGS. 11 and 12 illustrate the operations of the personal computer 1 andthe cellular telephone 11, respectively, in this modification.

Operations of steps S51 through S56 of the cellular telephone 11 shownin FIG. 12 are basically similar to those of steps S11 through S16 ofFIG. 10. The process shown in FIG. 12 is different from that of FIG. 10in that, in step S52, instead of the device name, the ID number isrequested from the personal computer 1, and the data sent in step S53 isnot the device name, but the ID number. Operations other than steps S52and S53 are similar to those of FIG. 10.

Similarly, operations in steps S31 through S37 of the personal computer1 shown in FIG. 11 are basically similar to those in steps S1 through S6of FIG. 9. In the process of FIG. 11, however, instead of the name ofthe Bluetooth device being directly sent from the cellular telephone 11,the ID number is sent. Accordingly, in step S34, the CPU 21 of thepersonal computer 1 stores the ID number of the cellular telephone 11 inthe RAM 23, and then, in step S35, the CPU 21 searches for the name ofthe Bluetooth device from the ID number of the cellular telephone 11.For searching for the device name, a table in which the ID number of thecellular telephone 11 is associated with the name of the Bluetoothdevice may be prestored in the storage unit 26. Alternatively, thecommunication unit 27 may access a predetermined server via, forexample, the Internet, so as to search for the name of the Bluetoothdevice corresponding to the ID number of the cellular telephone 11 viathis server.

The process after searching for the name of the Bluetooth device of thecellular telephone 11 is similar to that of FIG. 9.

A further explanation of examples of the operation executed in step S6of FIG. 9 (step S37 of FIG. 11) and the operation executed in step S16of FIG. 10 (step S56 of FIG. 12) is given below.

FIG. 13 illustrates an example in which a mail message registered in thecellular telephone 11 is enlarged and displayed on the LCD 32 of theinput display unit 2 by placing the cellular telephone 11 on the inputdisplay unit 2.

The processing performed by the cellular telephone 11 and the processingperformed by the personal computer 1 in this case are described belowwith reference to the flowcharts of FIGS. 14 and 15.

In step S71 of FIG. 14, the CPU 201 of the cellular telephone 11 readsthe senders and the subjects of mail messages received so far and storedin the RAM 203. Then, in step S72, the CPU 201 allows the communicationunit 213 to send the read senders and subjects of the mail messages tothe personal computer 1. That is, in this case, the CPU 201 controls thecommunication unit 213 to send the senders and subjects of the mailmessages to the personal computer 1 via Bluetooth communication.

The senders and subjects of the mail messages are displayed on the LCD32 of the personal computer 1, as described below, and when the userselects a predetermined sender and subject, information concerning thatselection is sent to the cellular telephone 11.

Then, in step S73, the CPU 201 waits until it is reported that the mailhas been selected, and when it is reported that the mail has beenselected, the process proceeds to step S74. In step S74, the mailmessage is read from the RAM 203 and is sent from the communication unit213 to the personal computer 1.

In accordance with the process of the cellular telephone 11, thepersonal computer 1 executes the process indicated by the flowchart ofFIG. 15.

First, in step S81, the CPU 21 receives the mail senders and subjectsfrom the cellular telephone 11. More specifically, the communicationunit 28 receives the mail senders and subjects from the communicationunit 213 of the cellular telephone 11 via Bluetooth communication, andsupplies them to the RAM 23 and stores them therein.

In step S82, the CPU 21 reads the senders and subjects stored in the RAM23, and outputs them to the LCD 32 and displays them. Accordingly, themail senders and subjects sent from the cellular telephone 11 aredisplayed in a window 301, such as that shown in FIG. 13.

The user operates the pen by viewing this display and specifies thesender or the subject of one of the mail messages within the window 301so as to select the mail. Then, in step S83, the CPU 21 waits until themail is selected, and when the mail is selected, the process proceeds tostep S84. In step S84, the CPU 21 informs the cellular telephone 11 ofthe selected mail. That is, in this case, the CPU 21 controls thecommunication unit 28 to inform the cellular telephone 11 which mail hasbeen specified (selected) by the user via Bluetooth communication.

After informing the cellular telephone 11 of the selected mail, asstated above, the selected mail message is sent from the cellulartelephone 11. Then, in step S85, the communication unit 28 receives themail message sent from the cellular telephone 11. The mail message istemporarily supplied to the RAM 23 and is stored therein. Then, in stepS86, the CPU 21 reads the mail message stored in the RAM 23, and outputsit to the right side of the position at which the cellular telephone 11is placed on the LCD 32 or to a position specified by the user with thepen (such a position is detected from an output of the tablet 31) anddisplays the message. Accordingly, the selected mail message isdisplayed in the window 302, such as that shown in FIG. 13. In theexample of FIG. 13, the message of the second mail (the sender is BBBand the subject is bb) in the window 301 is displayed as “Hello. It's anice weather, isn't it?”.

Theoretically, it is possible to send and receive mail data bycommunication between the RF tag 212 and the reader/writer 33. However,since the transmission capacity of this type of communication is small,the communication is limited to the sending of ID information in thepresent invention.

A display indicating the communication status in the informationprocessing system of the present invention is described below.

FIGS. 16 through 18 illustrate a first example of the display indicatingthe communication status in the information processing system of thepresent invention. When the cellular telephone 11 is positioned in theproximity with the personal computer 1, as shown in FIG. 16, and whenthe electric field formed by the cellular telephone 11 is sufficientlystrong at the position at which the personal computer 1 is disposed, theinput level of the radio waves transmitted from the cellular telephone11 and received by the communication unit 28 is sufficiently high.

When the input level of the radio waves transmitted from the cellulartelephone 11 is equal to the maximum input, the personal computer 1 setsthe level of transparency to be 0, and displays an image 321corresponding to the cellular telephone 11 on the LCD 32 of the inputdisplay unit 2 so that the background image is not transmitted at all.

When the cellular telephone 11 is positioned in a mid-point of thecommunication range of the personal computer 1 (for example, thedistance between the personal computer 1 and the cellular telephone 11is about 5 m), as shown in FIG. 17, and when the input level of theradio waves transmitted from the cellular telephone 11 and received bythe communication unit 28 is about one half the maximum input, thepersonal computer 1 sets the level of transparency to be, for example,50%, and displays the image 321 corresponding to the cellular telephone11 on the LCD 32 of the input display unit 2.

That is, the personal computer 1 adds, for example, ½ of thepredetermined pixel values of the original image 321 to ½ of the pixelvalues of the background image, thereby calculating the values of atranslucent image. The personal computer 1 then displays the translucentimage 321 corresponding to the cellular telephone 11 on the LCD 32 ofthe input display unit 2 based on the calculated pixel values.

When the cellular telephone 11 is positioned at the end of thecommunication range of the personal computer 1 (for example, thedistance between the personal computer 1 and the cellular telephone 11is about 10 m), as shown in FIG. 18, and when the input level of theradio waves transmitted from the cellular telephone 11 and received bythe communication unit 28 is about the same as the receptionsensitivity, the personal computer 1 sets the level of transparency tobe, for example, 90%, and displays the image 321 corresponding to thecellular telephone 11 on the LCD 32 of the input display unit 2.

That is, the personal computer 1 adds, for example, 10% of the pixelvalues of the original image 321 to 90% of the pixel values of thebackground image, thereby calculating the pixel values corresponding tothe image 321. The personal computer 1 then displays the almosttransparent image 321 corresponding to the cellular telephone 11 on theLCD 32 of the input display unit 2 based on the calculated pixel values.

FIG. 19 is a flowchart illustrating a process of displaying the radiowave status by the personal computer 1.

In step S101, the CPU 121 of the communication unit 28 of the personalcomputer 1 obtains the input level of the radio waves received from thecellular telephone 11 from an RF unit 128 via the bus 125. The CPU 121supplies data indicating the input level to the CPU 21 via theinput/output interface 126 and the input/output interface 25.

In step S102, the CPU 21 of the personal computer 1, which executes thedisplay control program 164, calculates the level of transparencycorresponding to the input level based on the data indicating the radiowaves. The CPU 21 calculates the level of transparency by, for example,dividing the obtained data indicating the input level by a predeterminedconstant.

The CPU 21 may determine the level of transparency by comparing the dataindicating the input level with at least one prestored threshold.Alternatively, the CPU 21 may determine the level of transparency basedon a table, which is prestored in the storage unit 26, in which theinput levels and the levels of transparency are associated with eachother.

In step S103, the CPU 21, which executes the display control program164, designates the level of transparency calculated in the processingof step S102 so as to display the image of the device of thecommunicating party on the LCD 32 of the input display unit 2. Theprocess then returns to step S101, and the display processing isrepeated. If the communicating party is, for example, the cellulartelephone 11, the CPU 21 designates the level of transparency calculatedin the processing of step S102 so as to display the image 321corresponding to the cellular telephone 11 on the LCD 32 of the inputdisplay unit 2.

As described above, the personal computer 1 is able to display the imageof a communicating party on the input display unit 2 by varying thelevel of transparency in accordance with the radio wave status. Thus,the user is able to quickly understand the radio wave status, namely,the communication status.

The user can determine the position of the cellular telephone 11 so thatthe image having the lowest level of transparency is displayed on theinput display unit 2, thereby making it possible to exchange informationmore reliably between the personal computer 1 and the cellular telephone11.

FIGS. 20 through 22 illustrate a second example of the displayindicating the communication status in the information processing systemof the present invention. When the cellular telephone 11 is placed inproximity with the personal computer 1, as shown in FIG. 20, and whenthe input level of the radio waves transmitted from the cellulartelephone 11 is equivalent to the maximum input, the personal computer 1displays an image 341 corresponding to the cellular telephone 11 at thecenter of the LCD 32 of the input display unit 2.

When the cellular telephone 11 is positioned at a mid-point of thecommunication range of the personal computer 1, as shown in FIG. 21, andwhen the input level of the radio waves transmitted from the cellulartelephone 11 and received by the communication unit 28 is about one halfthe maximum input, the personal computer 1 displays the image 341corresponding to the cellular telephone 11, for example, on a diagonalline of the display surface of the LCD 32 at which the distance from theimage 341 to the center of the LCD 32 and the distance from the image341 to the corner of the LCD 32 are the same.

When the cellular telephone 11 is positioned at the end of thecommunication range of the personal computer 1, as shown in FIG. 22, andwhen the input level of the radio waves transmitted from the cellulartelephone 11 and received by the communication unit 28 is almost equalto the reception sensitivity, the personal computer 1 displays the image341 corresponding to the cellular telephone 11 at the corner of the LCD32 of the input display unit 2.

FIG. 23 is a flowchart illustrating another process of displaying theradio wave status by the personal computer 1.

In step S121, the CPU 121 of the communication unit 28 of the personalcomputer 1 obtains the input level of the radio waves received from thecellular telephone 11 from the RF unit 128 via the bus 125. The CPU 121then supplies data indicating the input level to the CPU 21 via theinput/output interface 126 and the input/output interface 25.

In step S122, the CPU 21 of the personal computer 1, which executes thedisplay control program 164, calculates the display position based onthe data indicating the input level of the radio waves. For example,when the input level of the radio waves is higher, the CPU 21 calculatescoordinates closer to the center of the LCD 32 on a diagonal line of thedisplay surface of the LCD 32. When the input level of the radio wavesis lower, the CPU 21 calculates coordinates closer to the corner of theLCD 32 on a diagonal line of the display surface of the LCD 32.

In step S123, the CPU 21, which executes the display control program164, designates the display position corresponding to the input levelcalculated in the processing of step S122 so as to display the image ofthe device of the communicating party. The process then returns to stepS121, and the display processing is repeated. If the communicating partyis, for example, the cellular telephone 11, the CPU 21 designates thedisplay position calculated in the processing of step S122 so as todisplay the image 341 corresponding to the cellular telephone 11 on theLCD 32 of the input display unit 2.

As described above, the personal computer 1 is able to display the imageof a communicating party on the input display unit 2 by varying theposition in accordance with the radio wave status. Then, the user isable to quickly understand the radio wave status, namely, thecommunication status.

The user can determine the position of the cellular telephone 11 so thatthe image is displayed at a position closer to the center of the inputdisplay unit 2, thereby making it possible to exchange information morereliably between, the personal computer 1 and the cellular telephone 11.

The personal computer 1 may display the image of a communicating partyon the input display unit 2 by changing the size of the image inaccordance with the radio wave status. For example, when the input levelof the radio waves transmitted from the cellular telephone 11 is higher,the personal computer 1 may display a larger image of the communicatingparty on the input display unit 2. When the input level of the radiowaves transmitted from the cellular telephone 11 is lower, the personalcomputer 1 may display a smaller image of the communicating party on theinput display unit 2.

Alternatively, the personal computer 1 may perform mosaic processingcorresponding to the radio wave status on the image of a communicatingparty so as to display the image subjected to mosaic processing on theinput display unit 2. For example, when the input level of the radiowaves transmitted from the cellular telephone 11 is sufficiently high,the personal computer 1 displays a sharp image of the communicatingparty on the input display unit 2. When the input level of radio wavestransmitted from the cellular telephone 11 is low, the personal computer1 displays a mosaic-processed image of the communicating party on theinput display unit 2. The personal computer 1 varies the level of mosaicprocessing performed on the image of the communicating party inaccordance with the input level of the radio waves transmitted from thecellular telephone 11.

Alternatively, the personal computer 1 may display the image of acommunicating party on the input display unit 2 by changing the color ofthe image in accordance with the radio wave status. For example, whenthe input level of the radio waves transmitted from the cellulartelephone 11 is higher, the personal computer 1 displays a highersaturation image (a so-called sharp image) of the communicating party onthe input display unit 2. When the input level of the radio wavestransmitted from the cellular telephone 11 is lower, the personalcomputer 1 displays a lower saturation image (a so-called faint image)of the communicating party on the input display unit 2. The personalcomputer 1 may display the image of a communicating party on the inputdisplay unit 2 by changing the color density, the color hue, or theluminance of the image in accordance with the radio wave status.

Alternatively, the personal computer 1 may display the image of acommunicating party on the input display unit 2 by changing the spatialresolution of the image in accordance with the radio wave status. Forexample, when the input level of the radio waves transmitted from thecellular telephone 11 is higher, the personal computer 1 may display animage containing more high-frequency components of the communicatingparty on the input display unit 2. When the input level of the radiowaves transmitted from the cellular telephone 11 is lower, the personalcomputer 1 may display an image containing less high-frequencycomponents (a so-called blurred image) of the communicating party on theinput display unit 2.

The personal computer 1 may display on the input display unit 2 an imageobtained by changing the level of transparency, the size, thesaturation, etc. in a mixed manner in accordance with the radio wavestatus.

It has been described that the personal computer 1 displays the imagecorresponding to the input level of the radio waves received by thecommunication unit 28 on the input display unit 2. However, the personalcomputer 1 may display the image corresponding to the intensity ofelectromagnetic coupling between the reader/writer 33 and the RF tag 212on the input display unit 2.

The ID number is sent and received between the RF tag and thereader/writer. Alternatively, a barcode may be printed on eachelectronic device, and the ID number can be sent and received by readingthe barcode.

Although Bluetooth is used as a network by way of example, a telephoneline, a LAN, a wireless LAN, a WAN, the Internet, etc., may be used.

As the information processing apparatus on which an electronic device isplaced, not only an input display unit, but also a palm rest, a mousepad, or a white board of a notebook personal computer may be used.

It has been described that the telephone number is used as the ID numberby way of example. However, any number may be used as long as it isrequired for accessing the electronic device in the network.

Authentication for a communicating party may be performed when sendingand receiving the ID number.

The terminal of a communicating party performing Bluetooth communicationis specified based on the ID or the name of the Bluetooth device storedin the RF tag 212 of the cellular telephone 11. However, even if the RFtag 212 is not provided for the cellular telephone 11, the terminal ofthe communicating party can be specified by controlling the output powerof the radio waves of the communication unit 213, which serves as awireless module (Bluetooth module).

A description is now given of a communication system in which theterminal of a communicating party can be specified by controlling theoutput power of radio waves output from a wireless module.

FIG. 24 is a diagram illustrating an example of the configuration of thecommunication system in which the terminal of a communicating party canbe specified by controlling the output power of radio waves.

In this example, although a description is given of communicationbetween the personal computer 1 and a PDA 501, the same operation can beperformed when the cellular telephone 11 is used instead of the PDA 501.

For example, when a communicating party performing Bluetoothcommunication is specified to establish communication with thatcommunicating party, the PDA 501 first restricts the output power of acommunication module 511 to a minimal level so that radio waves reachonly within a range of a few centimeters. In the extremely small powermode in which the output power of radio waves is restricted as describedabove, the communication module 511 repeatedly performs “inquiry” tosearch for devices positioned in a range that can be reached by theradio waves (for example, within a range of a few centimeters).

When the user places or positions the PDA 501 on or in proximity withthe personal computer 1 so that the radio waves radiated from thecommunication module 511 are received by the communication unit 28(wireless module) of the personal computer 1, the communication unit 28responds to the inquiry. Thus, the communication module 511 performsinquiry and paging with the communication unit 28, as stated above, soas to establish a communication link. This communication link iseffective only within a very narrow area that can be reached by radiowaves from the communication module 511 in which the extremely low powermode is set.

Accordingly, the communication module 511 temporarily disconnects thecommunication link so as to switch the power mode of the communicationmodule 511 from the extremely low power mode to the normal power mode sothat communication can be performed with the communication unit 28 evenif the PDA 501 is away from the personal computer 1 at a certaindistance. Then, the communication module 511 reestablishes thecommunication link with the communication unit 28 based on theinformation obtained (the information obtained by inquiry and paging inshort-distance communication).

The reestablished communication link becomes effective within a range ofa few dozen of meters that can be reached by radio waves in a mannersimilar to normal Bluetooth communication, and Bluetooth communicationcan be performed even when the distance between the personal computer 1and the PDA 501 is sufficiently wide.

As described above, even when an RF tag in which the ID or the name of aBluetooth device is stored is not provided for the PDA 501, the outputpower of the communication module is controlled, and then, the usermerely places the PDA 501 in proximity with the personal computer 1 toestablish Bluetooth communication.

If the power mode of the communication module 511 can be seamlesslyswitched, it may be switched from the extremely low power mode to thenormal power mode without temporarily disconnecting the communicationlink established when the extremely low power mode is set.

FIG. 25 is a block diagram illustrating an example of the configurationof the PDA 501 shown in FIG. 24.

The configuration of the PDA 501 is basically similar to that of thecellular telephone 11 shown in FIG. 6, except that the communicationunit 209 (a communication module that performs communication via atelephone line), the microphone 210, the speaker 211, and the RF tag 212are not provided, and an explanation thereof is thus omitted.

A CPU 521 controls the overall operation of the PDA 501 according to,for example, a program expanded from a ROM 522 into a RAM 523, andcontrols the output power of radio waves transmitted from thecommunication module 511 according to the communication status, asdescribed above.

FIG. 26 is a block diagram illustrating an example of a detailedconfiguration of the communication module 511 shown in FIG. 25.

The communication module 511 can be a Bluetooth module or a wireless LANmodule, and if it serves as a Bluetooth module, the configurationthereof encompasses the configuration of the communication unit 28 shownin FIG. 4. The configuration of the communication module (Bluetoothmodule) 511 in FIG. 26 is shown in a simplified form compared to thatshown in FIG. 4 so as to avoid the repetition of the same explanation.

A wireless controller 541 controls a changeover switch 544. When sendinginformation to an external terminal from the communication module 511,the wireless controller 541 connects a switch 544A to a contact a. Whenreceiving information from an external terminal, the wireless controller541 connects the switch 544A to a contact b. Based on the controlperformed by the CPU 521 via the bus 524 and the input/output interface525, the wireless controller 541 controls the gain of a power amplifier545 so as to regulate the range (output power) that can be reached byradio waves radiated from an antenna 547.

More specifically, when an instruction is given from the CPU 521 to setthe extremely low power mode, the wireless controller 541 controls thegain of the power amplifier 545 so that the range that can be reached byradio waves radiated from the antenna 547 is restricted to a minimallevel. In contrast, when an instruction is given from the CPU 521 toswitch from the extremely low power mode to the normal power mode afterspecifying the terminal of a communicating party, the wirelesscontroller 541 controls the gain of the power amplifier 545 so that therange that can be reached by radio waves becomes wider.

As in the baseband controller 127 shown in FIG. 4, a baseband controller542 controls the baseband signal of transmission/reception signals. Amodulation/demodulation processor 543 performs GFSK modulation andspread spectrum based on the hopping frequency on the output from thebaseband controller 542, and outputs the resulting signal from theantenna 547 via the power amplifier 545. The modulation/demodulationprocessor 543 also performs inverse spread spectrum and GFSKdemodulation on the output from an LNA (Low Noise Amplifier), andoutputs the resulting signal to the baseband controller 542.

The configuration of the personal computer 1 is similar to theconfiguration shown in FIG. 2, and an explanation thereof is thusomitted. In the communication system shown in FIG. 24, it is notnecessary that the reader/writer 33 shown in FIG. 2 be provided for thepersonal computer 1.

The operation of the communication system shown in FIG. 24 is describedbelow with reference to the flowchart of FIG. 27. In this example, it isassumed that a communicating party performing Bluetooth communication isspecified to establish communication.

For example, when an instruction is given from the user to performBluetooth communication, the communication module 511 is started underthe control of the CPU 521. In step S201, the extremely low power modeis set as the power mode of the communication module 511. Thecommunication module 511 then proceeds to step S202 in which itrepeatedly performs inquiry to search for a terminal placed in proximitywith the PDA 501. Since the extremely low power mode is set to limit therange that can be reached by radio waves to a minimal level, during theinquiry performed in step S202, an IQ packet (inquiry packet) isrepeatedly broadcast in a range of a few centimeters from the antenna547.

Meanwhile, in step S211, the communication unit 28 of the personalcomputer 1 repeatedly performs inquiry scanning and paging scanning, andwaits for an inquiry or paging request from another terminal.

When the user places the PDA 501 in proximity with the personal computer1, and when the communication unit 28 of the personal computer 1 iswithin the range that can be reached by radio waves from thecommunication module 511 of the PDA 501, an IQ packet broadcast from thecommunication module 511 is received by the communication unit 28 instep S222.

Upon receiving the IQ packet broadcast from the communication module511, the communication unit 28 proceeds to step S223 to respond to theIQ packet. In step S223, the communication unit 28 sends an FHS packetto the communication module 511. This FHS packet contains informationindicating the Bluetooth address and the Bluetooth clock of the personalcomputer 1 as attribute information of the personal computer 1(Bluetooth slave).

Upon receiving the FHS packet sent from the communication unit 28 instep S203, the communication module 511 proceeds to step S204 in whichthe communication module 511 requests the communication unit 28 toconnect to the communication module 511.

More specifically, when the ID packet is sent from the communicationmodule 511 to the communication unit 28, and when the same ID packet asthe ID packet sent from the communication module 511 is returned fromthe communication unit 28 to the communication module 511, an FHS packetcontaining the Bluetooth address and the Bluetooth clock of thecommunication module 511 is sent from the communication module 511 tothe communication unit 28.

When receiving the FHS packet sent from the communication module 511 bythe communication unit 28 in step S224, synchronization in the frequencydomain (frequency hopping pattern) and in the time domain (time slot) isestablished between the communication module 511 and the communicationunit 28, thereby entering the state in which a data link (communicationlink) is established (state 1).

For example, when a data link is first established between thecommunication unit 28 and the communication module 511 by Bluetooth, instep S205, the communication module 511 sends a PIN (PersonalIdentification Number) code to the communication unit 28 so as toauthenticate each other. The PIN code sent from the communication module511 is received by the communication unit 28 in step S225, and then,various link keys are set between the communication module and thecommunication unit 28 based on the PIN code, random numbers, etc. ThePIN code may be encrypted before being sent and received by using apublic key provided for the communication module 511 by thecommunication unit 28. That is, in this case, the communication unit 28manages the private key associated with the public key provided for thecommunication module 511. Accordingly, the security can be enhanced,thereby making it possible to perform Bluetooth communication morereliably only between the personal computer 1 and the PDA 501.

The communication link established as described above is effective onlyin a range of a few centimeters that can be reached by radio wavesradiated from the communication module 511 in which the extremely lowpower mode is set. Accordingly, in step S206, the communication module511 requests the communication unit 28 to temporarily disconnect thedata link so as to switch the power mode so that the communicationmodule 511 can communicate with the communication unit 28 even if it isaway from the communication unit 28 at a certain distance. In this case,the information obtained so far, that is, the Bluetooth address, PINcode, etc., of the communication unit 28, is stored in the communicationmodule 511.

Upon receiving this request in step S226, as in the communication module511, the communication unit 28 stores the information obtained so far,i.e., the Bluetooth address, PIN code, etc., of the communication module511, and disconnects the data link (state 2).

In step S207, the communication module 511 sets the power mode thatcontrols the output power to the normal power mode under the control ofthe CPU 521 so as to reestablish a data link with the communication unit28. Accordingly, Bluetooth radio waves from the communication module 511can reach up to, for example, a range of a few dozen of meters.

The communication module 511 then proceeds to step S208. In step S208,the communication module 511 specifies the personal computer 1 as theterminal of the communicating party based on the information storedimmediately before the data link is disconnected, and requests thecommunication unit 28 to connect to the communication module 511.

This request is received by the communication unit 28 in step S227, andthe settings are made in both the terminals so as to establish the datalink between the communication module 511 and the communication unit 28.That is, in this state, Bluetooth communication can be performed, forexample, within a range of a few dozen of meters that can be reached byradio waves radiated from the communication module 511 in which thenormal power mode is set (state 3).

The communication system shown in FIG. 24 in which a closely placedterminal can be specified as the terminal of a communicating party isapplied to the information processing system formed of the personalcomputer 1 and the cellular telephone 11 shown in FIG. 1. Then, in thisinformation processing system, the image indicating the closely placedterminal can be displayed on the LCD 32 of the personal computer 1 inaccordance with the distance between the terminal of the communicatingparty and the personal computer 1. That is, the user is able torecognize the communication distance at which the terminals can beconnected, thereby making it possible to reliably perform communicationbetween the terminals.

A set of the above-described processes can be executed by usingsoftware. In this case, a corresponding software program is installedinto a computer built in dedicated hardware or a computer that canexecute various functions by installing various programs, for example, ageneral-purpose computer, via a network or a recording medium.

This recording medium may be formed of a package medium recording theprogram therein, which is distributed to the user for providing theprogram separately from the computer, as shown in FIG. 2, consisting ofthe magnetic disk 41 (including a floppy disk (registered)), the opticaldisc 42 (including a CD-ROM (Compact Disc-Read Only Memory) and a DVD(Digital Versatile Disc)), the magneto-optical disk 43 (including an MD(Mini-Disc (registered)), or the semiconductor memory 43. Alternatively,the recording medium may be formed of the ROM 22 recording the programtherein or a hard disk contained in the storage unit 26, which isprovided to the user while being built in the computer.

The steps forming the program recorded in the recording medium encompassoperations executed in chronological order described in thisspecification. The steps also encompass operations concurrently orindividually performed.

In this specification, the system represents the entire apparatusconsisting of a plurality of devices.

INDUSTRIAL APPLICABILITY

As described above, according to the present invention, communicationcan be performed with an electronic device via radio waves, and thedisplay of an image corresponding to the electronic device is controlledbased on the input level of the radio waves transmitted from theelectronic device, thereby making it possible to recognize thecommunication distance at which the information processing apparatus andthe electronic device can be connected. Thus, information can bereliably exchanged between the information processing apparatus and theelectronic device.

1. An information processing apparatus, comprising: communication meansfor communicating, via radio waves, with a movable electronic device, aninput level of the radio waves having a predetermined relationship witha distance between the movable electronic device and the informationprocessing apparatus; obtaining means for obtaining identificationinformation concerning the electronic device; a display screen fordisplaying an image representing the electronic device specified fromthe identification information, a display location of the image on thedisplay screen having a predetermined relationship with the input levelof the wave radios; and display control means for controlling display ofthe image on the display screen based on data indicating the input levelof the radio waves transmitted from the electronic device, a level ofsaturation of the image corresponding to the input level of the radiowaves, and the electronic device being located within a communicationrange of the communication means, wherein when a user moves theelectronic device around the information processing apparatus, thedisplay control means changes the display location of the image on thedisplay screen, for the user to determine, based on the display locationof the image on the display screen, a location to place the electronicdevice for performing a reliable data communication between theelectronic device and the information processing apparatus.
 2. Theinformation processing apparatus according to claim 1, wherein: theobtaining means obtains the identification information concerning theelectronic device by one of a communication system in which informationis sent and received by electromagnetic waves and a Bluetoothcommunication system in which a communicating party is specified bysearching for devices in an extremely lower power mode; and thecommunication means communicates with the electronic device based on theidentification information.
 3. The information processing apparatusaccording to claim 1, wherein the display control means controls theimage to be displayed with a level of resolution corresponding to theinput level of the radio waves.
 4. The information processing apparatusaccording to claim 1, wherein the display control means controls theimage to be displayed by performing mosaic processing on the image inaccordance with the input level of the radio waves.
 5. The informationprocessing apparatus according to claim 1, wherein the obtaining meansobtains the image representing a configuration of the electronic devicefrom the electronic device specified by the identification information.6. The information processing apparatus according to claim 1, whereinwhen the user moves the electronic device around the informationprocessing apparatus, the display control means changes a transparencylevel of the image on the display screen, for the user to determine,based on the transparency level of the image, the location to place theelectronic device for performing the reliable data communication betweenthe electronic device and the information processing apparatus.
 7. Theinformation processing apparatus according to claim 1, wherein thepredetermined relationship between the display location of the image onthe display screen with the input level of the wave radios includes: thedisplay location of the image is at a center location of the displayscreen when the input level of the wave radios is at a maximum level;and the display location of the image is at a corner location of thedisplay screen when the input level of the wave radios is at a receptionsensitivity level.
 8. The information processing apparatus according toclaim 1, wherein the predetermined relationship between the displaylocation of the image on the display screen with the input level of thewave radios further includes: the display location of the image is at amiddle point on a diagonal line of the display screen when the inputlevel of the wave radios is at one half of the maximum level.
 9. Theinformation processing apparatus according to claim 1, wherein thedisplay control means controls the image to be displayed with a sizecorresponding to the input level of the radio waves.
 10. An informationprocessing method, implemented by an information processing apparatushaving at least one processor, comprising: a communication processingstep of communicating, via radio waves, with a movable electronicdevice, an input level of the radio waves having a predeterminedrelationship with a distance between the movable electronic device andthe information processing apparatus; an obtaining processing step ofobtaining identification information concerning the electronic device;and a display control processing step of controlling display of an imagerepresenting the electronic device specified from the identificationinformation on a display screen of the information processing apparatusbased on data indicating the input level of the radio waves transmittedfrom the electronic device, a level of saturation of the imagecorresponding to the input level of the radio waves, the electronicdevice being located in a communication range of the informationprocessing apparatus, and a display location of the image on the displayscreen having a predetermined relationship with the input level of thewave radios, wherein controlling the display of the image includes: whena user moves the electronic device around the information processingapparatus, changing the display location of the image on the displayscreen, for the user to determine, based on the display location of theimage on the display screen, a location to place the electronic devicefor performing a reliable data communication between the electronicdevice and the information processing apparatus.
 11. The informationprocessing method according to claim 10, wherein controlling the displayof the image further includes: when the user moves the electronic devicearound the information processing apparatus, changing a transparencylevel of the image on the display screen, for the user to determine,based on the transparency level of the image, the location to place theelectronic device for performing the reliable data communication betweenthe electronic device and the information processing apparatus.
 12. Theinformation processing method according to claim 10, wherein thepredetermined relationship between the display location of the image onthe display screen with the input level of the wave radios includes: thedisplay location of the image is at a center location of the displayscreen when the input level of the wave radios is at a maximum level;and the display location of the image is at a corner location of thedisplay screen when the input level of the wave radios is at a receptionsensitivity level.
 13. The information processing method according toclaim 10, wherein the predetermined relationship between the displaylocation of the image on the display screen with the input level of thewave radios further includes: the display location of the image is at amiddle point on a diagonal line of the display screen when the inputlevel of the wave radios is at one half of the maximum level.
 14. Theinformation processing apparatus according to claim 10, wherein thedisplay control means controls the image to be displayed with a sizecorresponding to the input level of the radio waves.
 15. Acomputer-readable medium, tangibly embodied in a storage device, havinginstructions recorded thereon which, when executed on a computer system,cause an information processing apparatus to perform the followingsteps: a communication processing step of communicating, via radiowaves, with a movable electronic device, an input level of the radiowaves having a predetermined relationship with a distance between themovable electronic device and the information processing apparatus; anobtaining processing step of obtaining identification informationconcerning the electronic device; and a display control processing stepof controlling display of an image representing the electronic devicespecified from the identification information on a display screen of theinformation processing apparatus based on data indicating the inputlevel of the radio waves transmitted from the electronic device, a levelof saturation of the image corresponding to the input level of the radiowaves, the electronic device being located within a communication rangeof the information processing apparatus, and a display location of theimage on the display screen having a predetermined relationship with theinput level of the wave radios, wherein controlling the display of theimage includes: when a user moves the electronic device around theinformation processing apparatus, changing the display location of theimage on the display screen, for the user to determine, based on thedisplay location of the image on the display screen, a location to placethe electronic device for performing a reliable data communicationbetween the electronic device and the information processing apparatus.16. The computer-readable medium according to claim 15, whereincontrolling the display of the image further includes: when the usermoves the electronic device around the information processing apparatus,changing a transparency level of the image on the display screen, forthe user to determine, based on the transparency level of the image, thelocation to place the electronic device for performing the reliable datacommunication between the electronic device and the informationprocessing apparatus.
 17. The computer-readable medium according toclaim 15, wherein the predetermined relationship between the displaylocation of the image on the display screen with the input level of thewave radios includes: the display location of the image is at a centerlocation of the display screen when the input level of the wave radiosis at a maximum level; and the display location of the image is at acorner location of the display screen when the input level of the waveradios is at a reception sensitivity level.
 18. The computer-readablemedium according to claim 15, wherein the predetermined relationshipbetween the display location of the image on the display screen with theinput level of the wave radios further includes: the display location ofthe image is at a middle point on a diagonal line of the display screenwhen the input level of the wave radios is at one half of the maximumlevel.
 19. The information processing apparatus according to claim 15,wherein the display control means controls the image to be displayedwith a size corresponding to the input level of the radio waves.